[9fans] hacking plan 9 on xen

[9fans] hacking plan 9 on xen

[Ronald G. Minnich]

first, you really ought to fix up the password for bootes. So do that, and 
don't come back until you do. I'll wait right here. 

All done? 

Second, you're going to have fun with the networking. Currently, 
the plan 9 domain will configure it's ip as 172.16.233.201. This 
is a hangover from vmware. 

Xen uses the linux bridge device to bridge domainX (X > 0) to dom0
(control domain).  Something about xen-br0 is not working right for me. So
to make networking go, I have to:

ifconfig -a
((see which vifx.0 is there ... let's say it is vif1.0))
ifconfig xen-br0 down
brctl delbr xen-br0
ifconfig vif1.0 172.16.233.200

Can somebody figure this out before I do and tell me what I've got wrong?  
It's some silly thing I've got with the xen-br0 device.  There were no
issues of this kind on xen under vmware ... weird. Packets just are not
making it across xen-br0. 

Then you can
ping 172.16.233.201 (should work)
(if that works, ...)
drawterm -a 172.16.233.201 -c 172.16.233.201

If this does not work, tell me.

Ok, suppose you're in and you want to build a kernel. I make no apologies
for my code, this is alpha stuff and involved Ron Learns The Kernel For
Real and Ron Learns Xen For Real and Ron Learns He Did Not Really Learn
Xen OR The Kernel For Real So He Rips It All Up And Tries Again. Followed
by Ron's Shift Key Finger Hurts. I've had a couple of these
rip-up-and-retry experiences as Xen and Plan 9 do not have the same kind
of common world view that Xen and Linux have. It's been interesting.

Also, the main include files are:
xen and xenmach.h. You really should not mod these. They are built by a 
shell script from .h files in the xen tree. I dumped all the files into 
two files because 8c is fast as hell and I see no real need to have them 
broken out into the usual 20 files with the usual GNU style 
#ifdef I_HAVE_INCLUDED_THAT_OTHER_INCLUDE_FILE 
crap. 

login as bootes. 
. xenbind
(do an ns for fun -- make sure that /usr/bootes/src/xen2.0/whatever is 
bound over the top of /sys/src/9/whatever)
cd /sys/src/9/pc
mk 'CONF=pc'

This will give you a 9pc kernel. Yes, I know the one you boot is 9pccpu,
this is more of my paranoia w.r.t. making sure I don't blow away a working
kernel, so just Deal With It.

cp 9pc /mnt/term/whatever/9pccpu
or
modify the copyit script

Then you can boot your own kernel. 

WARNING: ALWAYS SAVE A KNOWN-GOOD KERNEL. It's real easy to drive yourself 
into a corner you can't get out of, then you can't boot any more. That's a 
real drag. So be careful out there. 

NOTE: you get NO debug messages from Xen unless you have 2 serial ports,
read the xen info to see why, so all the debug messages I might generate
via the dp() function (see the code) will go to the luminiferous aether.  
Don't expect to see them, therefore.

ron